Machine for and method of refrigerating



May 11 1926. 1,584,382

c; L. AIM. LEBLANC MACHINE FOR AND METHOD OF REFRIGERATING Filed Sept. 22, 1921 5 Sheets-Sheet; 1

fig.

May 11 1926. 7 1,584,382

C. L. A. M. LEBLANC MACHINE FOR AND METHOD OF REFRIGERATING Filed Sept. 22, 1921 5 Sheets-Sheet 2 May 11' 1926. 1,584,382

C. L. A. M. LEBLANC MACHINE FOR AND METHOD OF REFRIGERATING Filed Sept. 22, 1921 5 Sheets-Sheet' 5 May 11 ,1926.

C. L. A. M. LEBLANC MACHINE FOR AND METHOD OF REFRIGERATING I Filed Sept. 22, 1921 s Shets-Sheet 4 May .11 1926.

c. L. A. M. LEBLANC MACHINE FORYAND METHOD OF REFRIGERATING' Filed Sept. 22, 1921 5 Sheets-Sheet; 5

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Patented May 11,1926.

, UNITED STATES/- PATIENT OFFICE.

CHARLES LEoNAnnAnMAND MAURICE LEBLANC, or PARIS, FRANCE, AssIGNoR' TO socmm momma noun LEXPLOITA'IION. mas rnocnnns MAURICE LEIBLANO- YICKEBS, OF PARIS, FBANGE.

MACHINE- FOR AND .METHOD OF REFBIGERATING.

. lpp lioation filed September 2-2, 1921. Serial m. 502,508.

The invention relates to refrigerating machines and has particular relation to the type in which a gas, such as air, is-iirst (30111 pressed, causing it to risein temperature, 6 then circulated through a cooling device un.

der pressure in order to lower its temperature, then to expand the cooling gas to' cause it to lower still further in temperature, and

finally to circulate the gas through the re- 1 frigerator at a. pressure substantially equal to the internal pressure of the refrigerator, from whence it is withdrawn and again subjected to the cyeleof operations outlined above.

One of the objects of the present invention is to provide a machine, of the character described, which embodies a double acting compressor and expander that will first compress a body of gas delivered thereto from a refrigerator, thereby causing its temperature to rise; then to subject the gas under pressure to the action of a cooler and at the same time replacing it by gas from the cooler which is under the same pressure but of a lower temperature; then expanding this cold gas to further reduce its temperature; then to deliverthis latter body of cold gas to the refrigerator from which itoriginally issued and replacing it in the expanderby the warm air displaced thereby n'thc refrigerator. v

Another object of the invention is to provide a machine, of the class designated, which embodies an auxiliary compressor which is adapted to'supplement. the volume of gas within the cooling device in order to compensate for thedecrease in the volume thereof caused by the cooling action of said device.

penditure of power. I

With such objects in view,as .well as other advantages which may be incident to the use of the improvements, the invention consists 1n the procedure and in the use of the A further object of the invention is to provide a machine of the class described may be operated. with a relatively small exparts and combinations thereof hereinafter set forth and claimed, with the understand-- ing that theseveral necessary elements const1tu t1ng the same may be varied in proportions and arrangement without departing from the nature and scope of the invention'.'

In order to make the invention more clear- 1y understood there are'shown in the accoml panying drawings means for carrying the same into practical efi'ect, without limiting the improvements, in their useful applications, to the particularconstructions which, for the purpose of explanation, have been made the subject of illustration. In the said drawings z-- Fig. 1 represents diagrammatically a refrigerating machine using airin accordance with the invention.

Fig. 2 shows in transverse section one of the compression v or expansion spaces or' chambers of the main compressor.

Fig. 3 is an end view as seen from right to left of the said compressor. showing the control mechanism of the distribution valves of the said compressor.

Fg. 4. 's a vertical longitudinal section through the axis of the main compressor, showing the control mechanisms of the piston and the distribution valves.

Fig. 5 is a horizontal lon itudinal section through the axis of the said compressor showing the same mechanisms.

Fig. 6 is a diagram showing the variation v of the lift of the distribution values of the compressor in relation to the angle of rotation w of the control shaft of the main compressor.

Fig.

. Figs. 9 and 10 are transverse sections ofthe arrangement of piston stop in two dis tinct angular'positions.

Fig. 11 shows the profile of the cams oontrolling the mechanism actuating the valve of the main compressor.

7 shows the. profile of the cam controlling the alternating movement of the main compressor.

for origin.

In the following description the letters P ,V and T designate the pressure of the air,

its specific volume and its absolute temperature. If these quantities have the values P,, V T the air is said to be in the state I v, za According to the invention, for thepurpose of obtaining the described cycle of circulation, there is illustrated a refrigerating machine which comprises in general, a cooling device A, a refrlgerator B, a main compressor and expander D, and an auxiliary compressor G, which latter is adapted to draw per kg. of gas describing the cycle, a volume V -V at the pressure P from the refrigerator B and to transfer it to the cooling device A. The main compressor and expander D consists of a cylinder 0 which communicates at each end with chambers E and E. An intermittently operable double acting piston P is mounted within the cylinder O and is reciprocated by means of a piston rod which is in turn reciprocated by means of mechanism hereinafter to be described. l

The piston P is provided with oppositely extending plunger P which are adapted to alternately enter the chambers E and E to 1 6 vary the cubical contents thereof in the ratio Each of these chambers E and E is provided with four distributin valves which consist of slides or taps o suitable convalves (1 and a with its outlet through pipes 3 and 4.. The distributing valves 6 6 communicate with the inlet of the refrigerator B, through pipes 5 and 6 respectively, and the distributing valves b, 6 with its outlet through pipes 7 and 8.

All the distributing valves being closed, the piston moves rapidly from one end of its stroke to the other and dwells there; assuming that such dwell occurs wlthin the chamber E.

At this moment the chamber E is full or air under pressure in the state l? V T The chamber E is filled with relatively rarefied air in the state P V T Thedistributing valves a a, b b open quickly and remain open.

Fans 7', f actuated by motors g, cause air currents which impel: (1) the air in the chamber E at pressure P and temperature T sending it into the cooler and replacing it, in this chamber by air at pressure P but at temperature T, coming from the cooler; (2) the air in .the chamber E at pressure P, and temperature T,, send Similarly in replacing a volume of T; l by T: Moreover,

4 a TI E The result is that the main compressor D forces alarger volume of air into the cooler than is returned tothe compressor therefrom", but the volume of air thus lost will be supplemented in the refri erator by the auxiliary compressor C whic will return it into the cooler.

Once the impelling is effected, the opendistributing valves a, a, 6 and 6 are rapidly closed whereupon the piston moves quickly to, the other end of its stroke where it also dwells within the chamber E. It is now the distributing valves 6 b a, and a which open.

The diagram given by a Watts indicator taken on one face of the piston of the main compressor D is reduced to a simple adiabatic line (P V T P V T successively traversed in opposite directions. Its area will then be nil.

The compressor C requires no description since it possesses no particular features and may consist of any ordinary compressor.

. As regards the main compressor D, in order to make it function, its inherent resistances must be overcome and the fans operated.

It will be seen from the following that these inherent resistances are all naturally much reduced by reason of the operation itself. It may be said with high approximation that the work absorbed thereby is roportional at each instant to the work imparted to or taken from the air by the piston.

But the apparatus being double-acting the difference of the pressures supported by the piston will change-sign when the .latter reaches the middle of its stroke. In the first part it will take up a quantity of work which it will restore to the air during the second half.

The main compressor D may be of a variety offorms but the following is recommended To facilitate the impe-lling a square secassesses represented in section at right angles to the axls' of the piston on Fig. 2.

The distribution valves a, a 6 and b I I consist of plates. The plates at and a are situated face to face and occupy. substantially all of the space on the two opposite sides of the .chamber under consideration and which are supported on their respective valve seats. The valves b and b are similarly mounted on the two other sides of the chamber.

The pressure in-thechambers being always less than that of the cooler, the plates a and a which connect them together, are arranged as exit valves. The pressure in the space being always greater than that of the refrigerator, the valves andb which place these in communication are arranged as inlet valves. I

These valves consist of metallic plates an their seatings preferably comprise a soft packing hof rubber (Fig. 2).

The several plates are pressed on their seatings h by means of springs z and are opened tribution system of Fig. 3.

In Figs. 2 and 3 thefulcrums of the levers K which control the valves of the chamber E referred to and thoseof the chamber of the main compressor D are designated by 110 2 10 th 100, 200 6100,6200 a I a 2.0 61 6 220 Sets of levers shown 1n Flg. 3 determine the movement of the valves 11, a 6 b and those of the valves 6 b a a The. control of this mechanism is obtained from the shaft of the .motor which actuates the whole machine by means of an arrangement hereinafter explained in detail.

The impelling system will cost much less if the valves are of large section, are opened more rapidly and if more effecting it.

The arrangements adopted permit of a very large section being given to the valves. A diagram is drawn having as abscissae time is given for the angle w through which the main compressor D will have turned and as ordinates the distance .through which the piston will be displaced from its mean position- (Fig. 6). It will be brou ht as uickly as possible from one end 0 its stro (e to the other while the machine turns It is then left by levers K which control the dis-- At the moment when the piston stops the valves commence to open and while they are opening the machine will turn through an angle I The variations of the height to which a given valve will be raised as a function of,

the angle w are represented by the lower curve of Fig. 6.

Each valve will be partly open while the machine is turning through an angle n and fully open when and this once every turn."

The aim is to operate the piston and valves rapidly so that these will remain fully open as long as possible. I a

It will be observed in passing, that from the moment when the brought from one end of its stroke tothe other and then-temporarily rendered inactive it is necessar to an 1 it with work during the period when tli y ply 1t most often in acontinuous manner. This work should therefore be first stored in a flywheel to be next given back quickly. Th1s operation not bein possible without loss it is desirable to ren or as small as possible the work absorbed b the piston. This is one of the reasons wh the machine has been divided up and instead of using a single acting compressor alone, an auxiliary compressor is employed. with a double actmg main compressor so that the piston of the latter has only to overcome inherentreslstance.

The right is reserved, however, to employ in certain cases a single compressor wherein the piston ismade to move very slowly when it has generated the volume V,,V it will generate the volume if -V or after havin reduced the volume V to the volume V It will reduce again the latter to the volume V The preceding arrangements permit the impelling to be very economically effected. But the system must be so constructed as to reduce to a minimum the frictional resistances of the compressor D.

The displacement of the piston is effected by a cam L (Fig. 7) upon which roll two di-' ametrically opposite rollers Z and Z. The

piston is very quickly e motor will supcontour of this cam is obtained in the following manner.

Let A be the strokeof the piston. Tw'o centre 0 symmetrical with respect to a cen-V concentric arcs of circles having a common tre line a: and of radii R and R+A are drawn, each subtending'an angle. equal to in po two circular arcs and their connecting curves.

. Let r be the'radius of these rollers: if from numerous points of these circuits .taken as centers, arcs of radius r are described, their boundary will be theprofile tobe given to the cam.

The distance of the axes of the two rollers being constant and equal to 2R +A., their bearin may be carried on a single frame M M Figs. 4 and 5-). fixed to the piston rod.

differences of pressure.

' curves of-the above diagram,.a curve is, 011-. A tained-(Fig. 8 which maybe compared This frame will'be rigidly connected to rods N N (Figs. 4 and 5) which are engaged in fixed slides P .P,-by which they will be guided.

The friction of the piston rings and the extent of leaking by are proportional tothe diameter of the piston while the volume which it displaces is proportional to its square.

' It-will therefore be advisable for generating a given volume to give a very large di= ameter and a small stroke to the piston.

This is what has been done. This presents no inconvenience in practice, the undesirable space being relatively large and the cam being so much the easier to operate as the stroke of the piston is smaller. But with this arrangement considerable effort will be exerted on the piston by the There is no need for it to result in an increase in the inherent resistances of themachine.

Reverting to a diagram which consists of two adiabatic linesfsymmetrically disposed with respect tot-he ordinate passing through their centre, it is proved thatthe difierence of their ordinates is proportional at each instant to the difference of pressure supported by the piston.

If a curve is drawn taking for y the differen ces of these ordinates and for a; the distances of these ordinates to the centre of the very approximately with a linepassing through the origin of the co-ordinates. Thecircumstances are such asif the pistons were urged by a spring towards their middle po-" sitions.

Under these conditiona supposingthe is- 5 K i i I 'havingteeth Figs. 4, 5', 9 and 10. This 180 ton first to' be maintained at one end 0 its stroke-and then released, the difference. pf

netic energyto it and subsequently stop it. If it did not have to overcome friction it pressure which it supports will first'impart would go of itself to the other end of its stroke, during the time of which the path which it will have traversed will be a sinusoidal function of time of the form' tion N (in revolutions r second) of the. compressor D, or upon t e mass of the piston, the factor n, or finally on the pressure P, of the'air, the condition brake u on the cam.

In or er to avoid thiindefect the piston is In acting either upon the speed of rota- Fig. 11, displaced 180 with-respect to one 7 another and dis osed like the cams L upon the shafts of t e motor but on the other sides of the bearin s X, and X,; the rollers V, .and V are app 'ed to said cams and are disposed at the extremities of levers pivoted about the fixed points Y, and Y,. The other extremities ofthese levers act upon the disc I through the intermediary of rods Z Z furnished with ball joints. The roller pressed by one cam operates the system and maintains at the same time the other roller in contact with its cam. a

The cams in rotatin impart an oscillatory movement'to the iso I. They will be timed with respect to the cam L so that this movement will have the desired phase.

dog S into which the dog disc I carries an interiorlg ton can move from one end of its stroke to the other.

When the piston reaches one end of its stroke the dog Q moves beyond the dog S to one side or the other by a very small amount (Figs. 4 and 5).

The disc I then turns in one direction or the other by of a revolution. The dog S thus rotates through part of a tooth space and if the dog Q is released its teeth will come into engagement with the other teeth which it cannot pass, (Fig. 10).

The cam L has onlyto hold the piston still during the operation of the valvesg namely during a time 3,- Asshown in ate the disc I.

The machine thus constituted will have a very good performance because the work which it has to produce, that is the work successively imparted to and taken from the air, is much smaller than inthe old machine using air and also becausea special machine is available for its production wherein all the inherent resistances are reduced to a minimum. a

At the same time it is much lighter and less cumbersome than the old machines, its pistons dis lace only the volume V' -V per g. of air escribing the cycle instead of having to displace the volume V -H7 The air cooler may be omitted by closing the o cleof the machine throu h the atmosp ere, as may sometimes e advantageous. This arrangementwill be particularly appropriate for lowering a temperature above zero by thermometer as there will be no fear of the formation of snow in the machine and no need to take special precautions for removin it. x

In general, it W111 be preferable to supply always the'same quantity of air forming the cycle through a refrigerator. Thus not only is one nolonger concerned with snow but a higher pressure can be given to the air and, other conditions being equal the power of the machine be proportional to the pressure P Furthermore, the power of the heat exchangers ,(cooler and 'refrigerator) will also increase with the pressure P Very light machines which are also not. very cumbersome in respect to their power are thus available. As will be well understood,'the machine lends itself to the same applications as all refrigeration machines using ammonia, sulphurous acid, etc. 1

It will be understood that all the arrangements which have been described byway of example in no way limit the invention and that modifications may be introduced with.-

out departing from the scopeof the inven-' tion.

What I claim is 1. A method of refrigerating which consists in compressing abody of gas of relatively high temperature received from a refrigerator to effect a still further rise in the temperature thereof, circulating the gas under pressure through a cooling device, by

causing its displacement by a second body of gas at the same pressure and at a lower temperature received from said cooling device, expanding the second body of gas to cause a further lowering in the temperature thereof, delivering said second body of gas to the refrigerator by causing its displace ment by a third body of gas received, from the refrigerator, compressing the third body of gas, circulating the same through the cooling device by causing its displacement by means of the first mentioned body of gas received from said cooling device, exp and-. ing said first mentioned body of gas to cause a-further lowering of the temperature thereof, and circulating said first mentioned body of gas relatively cold through said refrigerator by causing its displacement by said second body of gas received from said refrigerator.

2. A method of refrigerating which consists' in compressing a volume of gas, cooling the gas while under compression, expanding the cooled gas so as to cause a further decrease in the temperature thereof, delivering said expanded gas to a refrigerator, removing the gas from the refrigerator and recation between said refrigerator and said I compressor and expander, means for establishing .communicatlon between said compressor and expander and said cooling device, impelling means for causing the circulation o a coolin -medium through said elements, valve mec anism disposed in each of said communicating means, and means for actuating said valve mechanism in timed relation with respect to the operation of said compressor and expander to permit said impelling means to first deliver gas at a' relatively low temperature to said compressor and expander to be compressed thereby, then to be circulated through said cooler, then to be expanded by said compressor and ex-' pander and finally to be delivered to said refrigerator.

4. A refrigerating machine comprising a refrigerator, a cooling device "associated therewith, a compressor and expander, associated with said refrigerator and said cooling device, means for establishing communication between said refrigerator and said compressor and expander, means for establish'ing. communication-between said "com-' pressor and expander and said cooling device, impelling means for causing the circulation of a cooling medium through said elements, valve mechanism disposed-1n each of said communicating means, means for actuating said valve mechanisms in timed relation with respect to the operation of said compressor and ex ander to' permit said impelling means to' rst deliver gas at a relatively lowv temperature to said compressor and expander," to be compressed thereby,

then-to be circulated through said cooler,

then to be ex ended by said compressor and expander an finallyrto be delivered to said refrigerator, and means for deducting a predetermined amount of gas from sa1d refrigerator and delivering it to said cooling device. I

a. A refrigerat ng machine comprising a refr1gerator,'-a cooling device assoc1ated therewith, a compressor and expander, associated with said refrigerator and said cooling device, means for establishingcommunication between said refrigerator and sa1d compressor and expander, means for establishing communication between said compressor and expander and said cooling device, impelling means for causing the circulation of a cooling medlum'through sa1d elements, valve mechanism disposed in each I of said. communicating means, means frigerator.

for actuating said valve mechanisms in timed relation with respect to the operation of said compressor andex ander to permit said-impelling means to rst deliver gas at a relatively low temperature to said compressor and" expander to be compressed thereby, then/to be'circulated through said cooler, then to be expanded by said compressor and expander and finally to be delivered to sa1d refrigerator, and an auxiliary compressor for supplementing the mass of gas in said cooling device bygas taken from said re- 6. A process for accomplishing refrigera- .tion by means of a gas such as air, which consists in compressing the air, in cooling it, in effecting the expansion of the air and ed cold air,

thereby coolingiiit, in impellin this expandw ch is intende for the production of cold, by air at the same pressure which has given up its cold, in com ressing.

to the initial pressure the said air w ich has given up its cold and has just been exchanged, and then, after compression, in im-' pellmg the sa1d air by air at the same pressure which has given up its heat, in compressing the excess of air which has given up its cold in orderto bring itback to the initial pressure, and in. recommencing the .cycle of operations.

means between said refrigerator and said compressor on each side of said piston,

means for opening and closing said communicatin means, means for lmpellmg com resse air from said compressor by air I at t e same pressure from said air cooler and means for simultaneously impelling expandedv air from said compressor by air at the same pressure from said refrigerator.

8. In an apparatus for accomplishing refrigeration by means of air, an air cooler,

a refrigerator, a main compressor having a piston adapted to reciprocate therein so as to compress air on one side thereof-to the pressure prevailing in the air cooler and to simultaneously expand air on the other sidethereof to the pressure prevailing in the refriger'ator, communicating means between sa1d-air cooler and sa1d compressor on each side of said piston, commumcating means between said refrigerator and said compressor on each side of said piston, means for opening and closing said communicating means, means for impelling compressed air from said compressor by air at the same pressure from said cooler, means for simultaneously impellmg expanded air from sa1d compressor by air at the same pressure from said refrigerator and an auxiliary compressor adapted to withdraw excessvair from said refrigerator and transfer it to said cooler;

9; In an apparatus for accomplishing refrlgeration by means of air, an air cooler, a refrigerator, a mam compressor having a piston adapted to reciprocate therein so as to compress airon one side thereof to the pressure prevailing in the air cooler and to simultaneously expand the air on the other side thereof to the pressure prevailing in the refrigerator, communicating means between said air cooler and said compressor on each side of said piston, communicating means between said refrigerator and said compressor on each side of said piston, means for opening and closing said commu nicating means, a fan for impelling com-- a piston in said compressor adapted to reciprocate so as to compress a1r 1n one ofsaid spaces to the pressure prevailing in the 'air cooler and to simultaneously expand air in the other of said spaces to the pressure prevailing in the refrigerator, communicating means between said air cooler and each of said spaces including valvesdisposed upon opposite sides of said spaces, communicating means between said refrigerator and each of said spaces including valves disposed upon opposite sides of said spaces and means for operating said valves in timed relation to the reciproca'tions of said piston.

11. In an apparatus for accomplishing refrigeration by means of air,-a main compressor having a piston adaptedto reciprocate therein so as to compress air on one side thereof and to simultaneously expand the air on the other side thereof, a driving shaft having a cam for reciprocating said piston so formed as to permit a natural movement of said piston under the impulse of pressure exerted by the compressed air on one side thereof and positive means for causing said piston to dwell at each end of its reciprocation.

12. In an apparatus for accomplishing refrigeration by means of air, a main compressor having a piston adapted to reciprocate therein so as to compress air on one side thereof and to simultaneously expand air on the other side thereof, a driving shaft having a cam for reciprocating said piston so formed as to permit a natural movement of said piston under the impulse of pressure exerted by the compressed air on one side thereof, a toothed dog connected to said piston so as to reciprocate therewith, an annular toothed dog surrounding said first dog and means for relatively rotating said dogs at each end of the reciprocation of said piston so as to prevent relative movement between said dogs and cause said piston to dwellat each end of its reciprocation.

13. In an apparatus for accomplishing refrigeration by means of air, a main compressor having a piston adapted to reciprocate therein so as to compress air on one side thereof and tosimultaneously expand air on the other side thereof, adriving shaft having a cam for reciprocating said piston so formed as to permit anatural movement of said piston under the impulse of pros sureexerted by the compressed air on one side thereof, a toothed. dog connected to said piston so as to reciprocate therewith, an annular toothed dog surrounding said first dog and means for rotating said annular dog at each end of the reciprocation of said piston so as to prevent relativev movement between said dogs and cause said piston to dwell at each end of its reciprocation.

In testimony whereof I have signed this specification.-

CHARLES LEONARD ARMANI) MAURICE LEBLANC. 

